This PR implements the ELF support for PostLink CFG in PGO analysis map as discussed in [RFC](https://discourse.llvm.org/t/rfc-extending-the-pgo-analysis-map-with-propeller-cfg-frequencies/88617/2). A later PR will implement the Codegen Support.
We have optimized the implementation of introducing the "matching and inference" technique into Propeller. In this new implementation, we have made every effort to avoid introducing new compilation parameters while ensuring compatibility with Propeller's current usage. Instead of creating a new profile format, we reused the existing one employed by Propeller. This new implementation is fully compatible with Propeller's current usage patterns and reduces the amount of code changes. For detailed information, please refer to the following RFC: https://discourse.llvm.org/t/rfc-adding-matching-and-inference-functionality-to-propeller/86238. We plan to submit the relevant changes in several pull requests (PRs). The current one is the first PR, which adds the basic block hash to the SHT_LLVM_BB_ADDR_MAP section. co-authors: lifengxiang1025 <lifengxiang@kuaishou.com>; zcfh <wuminghui03@kuaishou.com> Co-authored-by: lifengxiang1025 <lifengxiang@kuaishou.com> Co-authored-by: zcfh <wuminghui03@kuaishou.com> Co-authored-by: Rahman Lavaee <rahmanl@google.com>
yaml2obj should determine the program header offset (and other properties) based on the intended values rather than the final `sh_offset` of the section header. `setProgramHeaderLayout` uses section offsets for determining `p_offset`. Move section header overriding after `setProgramHeaderLayout` to prevent `ShOffset` from affecting program header `p_offset`. This change adjusts the timing of when the section header is overridden to ensure that the program headers are set correctly. More details [here](https://github.com/llvm/llvm-project/pull/126537#issuecomment-2700421989). --------- Signed-off-by: Ruoyu Qiu <cabbaken@outlook.com> Signed-off-by: Ruoyu Qiu <qiuruoyu@xiaomi.com> Co-authored-by: Ruoyu Qiu <qiuruoyu@xiaomi.com>
This PR simply moves the callsite anchors from the beginning of callsites to their end. Emitting the end of callsites is more sensible as it allows breaking the basic block into subblocks which end with control transfer instructions.
This fixes the issues with 0b054e2 This reverts commit b80ce054206db223ec8c3cd55fad510c97afbc9f.
This reverts commit 0b054e21f473e258fe0a886fea908fe8bb867bc8. Breaks many tests, see comments on #143845.
https://github.com/llvm/llvm-project/pull/92066 will be dependent on this change
Recently, we have been looking at some optimizations targeting individual calls. In particular, we plan to extend the address mapping technique to map to individual callsites. For example, in this piece of code for a basic blocks: ``` <BB>: 1200: lea 0x1(%rcx), %rdx 1204: callq foo 1209: cmpq 0x10, %rdx 120d: ja L1 ``` We want to emit 0x9 as the call site offset for `callq foo` (the offset from the block entry to right after the call), so that we know if a sampled address is before the call or after. This PR implements the decode/encode/emit capability. The Codegen change will be implemented in a later PR.
This removes unused variables and dead code in the method.
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